Car Maintenance, Repairs, and How-Tos. It’s both useful and empowering to know how to fix your own car. Whether you need to test the condition of your car battery, fix your AC, or simply change your tires, learn how with these step-by-step tutorials.. LIST OF COMMON FAILURES. Doubting your own analysis work? Take a look at our rogues gallery of common failures. Search by Car Make. Parts Removal Instructions.